The founder of the Liberty Reserve digital currency business has been arrested in Spain on money-laundering charges, Costa Rican authorities have said.

Officials in the Central American country said in a statement that Arthur Budovsky had been detained as part of an investigation that also involved US authorities.

Police raided three homes and five businesses linked to the Costa-Rica-based Liberty Reserve and seized papers and digital documents that will be turned over to US authorities, the statement said. A Russian citizen was also arrested in the case in Costa Rica on Friday and will be extradited to the US, it said.

Budovsky, a naturalised Costa Rican citizen, was detained on Friday. He had renounced his US citizenship and become a resident and citizen of Costa Rica, Costa Rican authorities said.

Liberty Reserve is a company that allows users to apply for an account by supplying a valid email address. Once a person signs up for an account, Liberty Reserve gives them a user name and an account number and they can start transferring money around the world, Costa Rican officials said.

They said the company shut its offices in Costa Rica in 2011. The website, however, had continued to operate, although it was offline on Monday.

According to Costa Rica police, Budovsky was sentenced in 2007 to five years' probation after pleading guilty in a New York court to charges he operated an illegal financial services business similar to Liberty Reserve.

Liberty Reserve's origins are obscure, but it had grown into one of the criminal underworld's best-known electronic currency systems, used by hackers the world over to discreetly move large sums of money across borders, experts say.

Liberty Reserve, which conducted its transactions in dollars, euros and roubles, operates as an anonymous, no-questions-asked alternative to the global banking system, said Aditya Sood, a computer science doctoral candidate at Michigan State University who has studied the electronic currency.

"You don't need to provide your full details, or personal information, or things like that," he said in a telephone interview. "There's no way to trace an account. That's the beauty of the system."

Offshore currency centres, generally set up in places beyond the reach of US or European law enforcement, can serve as middlemen between criminals and the mainstream financial world, brokering transactions that turn illegally obtained money into seemingly legitimate cash.

Sood said that despite prominent disclaimers warning against money laundering, the currency centres typically have little in the way of serious oversight.

"They don't care," he said. "They have no idea where the money is coming from or where the money is going. That's how they designed the model."

Liberty Reserve appears to have played an important role in laundering the proceeds from the recent theft of some $45m from two Middle Eastern banks, according to legal documents made public by US authorities earlier this month.

The complaint against one of the Dominican Republic gang members allegedly involved in the theft states that thousands of dollars' worth of stolen cash was deposited into two Liberty Reserve accounts via currency centres based in Siberia and Singapore.

The loss of Liberty Reserve has the potential to cause a "major upheaval" in the cybercrime economy, said the investigative-journalist-turned-security-researcher Brian Krebs, who added in a blogpost that hackers writing in underground forums were already buzzing with concern over frozen funds.